The present invention relates generally to a color image forming apparatus, such as a digital multi-color printing machine and a digital multi-color copying machine. More particularly the present invention relates to a color image forming apparatus including developing units each of which contains a developer of each of at least three primary colors to form a multi-color image.
It is known in the art to reproduce halftone or pastel color by reducing the density of dots. However the reduced density of dots makes the scattering of dots conspicuous, which is characteristic of the digital systems, thereby making it difficult to reproduce clear pastel or halftone color; particularly difficult in blue and red which are inherently deep color.